Looking through the failure it appears the problem happens in your blaze.groovy file line 102. According to the comment it is doing the following:

// stip first 4 lines of css to new css
Unix4j
    .tail(Tail.Options.s, 4, cssFile.toFile())
    .toFile(newCssFile.toFile())

The problem here is that the resolution for the variable cssFile apparently is not returning the file because it doesn't yet exist. I'm guessing (not a groovy user) that the line cssFile = fontBuildDir.resolve("font-mfizz.css") should actually create the missing file, but it doesn't appear to be working. After a little research it seems that some python package is not working correctly. Strangely enough during the installation of the Vagrant OS the package failed to download.

==> default: --2017-09-18 12:06:58--  http://people.mozilla.com/~jkew/woff/woff-code-latest.zip
==> default: Resolving people.mozilla.com (people.mozilla.com)... 
==> default: 63.245.214.133
==> default: Connecting to people.mozilla.com (people.mozilla.com)|63.245.214.133|:80... 
==> default: failed: Connection refused.
==> default: unzip:  cannot find or open woff-code-latest.zip, woff-code-latest.zip.zip or woff-code-latest.zip.ZIP.
==> default: /tmp/vagrant-shell: line 7: cd: woff: No such file or directory
==> default: make: *** 
==> default: No targets specified and no makefile found
==> default: .  Stop.
==> default: mv: 
==> default: cannot stat ‘sfnt2woff’
==> default: : No such file or directory

Since apparently the people.mozilla.com link is now completely dead, you have to get the package from here on github at https://github.com/ppicazo/sfnt2woff. This apparently is not a compiled version.

So basically no one can build this unless they created their Vagrant installation BEFORE the link went dead.

Found the vagrant bootstrap shell file, and adjusted the download path for sfnt2woff, but apparently who ever is releasing that package does not provide the make file and so the build fails.

Since I can't figure out how to make your build system work I'm going to attempt to compile it using the FontCustom project alone.

I have the same issue but before the Java error appears Python is throwing something. Here's the log:

Traceback (most recent call last):
  File "/var/lib/gems/1.9.1/gems/fontcustom-1.3.8/lib/fontcustom/scripts/generate.py", line 120, in <module>
    subprocess.call(['sfnt2woff', fontfile + '.ttf'])
  File "/usr/lib/python2.7/subprocess.py", line 522, in call
    return Popen(*popenargs, **kwargs).wait()
  File "/usr/lib/python2.7/subprocess.py", line 710, in __init__
    errread, errwrite)
  File "/usr/lib/python2.7/subprocess.py", line 1327, in _execute_child
    raise child_exception
OSError: [Errno 2] No such file or directory
error  `fontforge` compilation failed.

and after that Java comes up with:

[ERROR] Problem with script likey @ blaze.groovy:102
[ERROR] java.io.FileNotFoundException: ./build/font/font-mfizz.css (No such file or directory)

To me, this looks like it's already failing in the Python part when it looks for the .ttf file. However, in the build dir, there's a font-mfizz.ttf file. So I have no idea what's going on there.

Might it be that it's not only Java to blame here?